<?php
/**
 * @file
 * @ingroup Ajax
 */

if ( !defined( 'MEDIAWIKI' ) ) {
	die( 1 );
}

/**
 * Function converts an Javascript escaped string back into a string with
 * specified charset (default is UTF-8).
 * Modified function from http://pure-essence.net/stuff/code/utf8RawUrlDecode.phps
 *
 * @param $source String escaped with Javascript's escape() function
 * @param $iconv_to String destination character set will be used as second parameter
 * in the iconv function. Default is UTF-8.
 * @return string
 */
function js_unescape( $source, $iconv_to = 'UTF-8' ) {
	$decodedStr = '';
	$pos = 0;
	$len = strlen ( $source );

	while ( $pos < $len ) {
		$charAt = substr ( $source, $pos, 1 );
		if ( $charAt == '%' ) {
			$pos++;
			$charAt = substr ( $source, $pos, 1 );
			if ( $charAt == 'u' ) {
				// we got a unicode character
				$pos++;
				$unicodeHexVal = substr ( $source, $pos, 4 );
				$unicode = hexdec ( $unicodeHexVal );
				$decodedStr .= code2utf( $unicode );
				$pos += 4;
			} else {
				// we have an escaped ascii character
				$hexVal = substr ( $source, $pos, 2 );
				$decodedStr .= chr ( hexdec ( $hexVal ) );
				$pos += 2;
			}
		} else {
			$decodedStr .= $charAt;
			$pos++;
		}
	}

	if ( $iconv_to != "UTF-8" ) {
		$decodedStr = iconv( "UTF-8", $iconv_to, $decodedStr );
	}

	return $decodedStr;
}

/**
 * Function coverts number of utf char into that character.
 * Function taken from: http://www.php.net/manual/en/function.utf8-encode.php#49336
 *
 * @param $num Integer
 * @return utf8char
 */
function code2utf( $num ) {
	if ( $num < 128 )
		return chr( $num );
	if ( $num < 2048 )
		return chr( ( $num >> 6 ) + 192 ) . chr( ( $num&63 ) + 128 );
	if ( $num < 65536 )
		return chr( ( $num >> 12 ) + 224 ) . chr( ( ( $num >> 6 )&63 ) + 128 ) . chr( ( $num&63 ) + 128 );
	if ( $num < 2097152 )
		return chr( ( $num >> 18 ) + 240 ) . chr( ( ( $num >> 12 )&63 ) + 128 ) . chr( ( ( $num >> 6 )&63 ) + 128 ) . chr( ( $num&63 ) + 128 );
	return '';
}

/**
 * Called for AJAX watch/unwatch requests.
 * @param $pagename Prefixed title string for page to watch/unwatch
 * @param $watch String 'w' to watch, 'u' to unwatch
 * @return String '<w#>' or '<u#>' on successful watch or unwatch,
 *   respectively, followed by an HTML message to display in the alert box; or
 *   '<err#>' on error
 */
function wfAjaxWatch( $pagename = "", $watch = "" ) {
	if ( wfReadOnly() ) {
		// redirect to action=(un)watch, which will display the database lock
		// message
		return '<err#>';
	}

	if ( 'w' !== $watch && 'u' !== $watch ) {
		return '<err#>';
	}
	$watch = 'w' === $watch;

	$title = Title::newFromDBkey( $pagename );
	if ( !$title ) {
		// Invalid title
		return '<err#>';
	}
	$article = new Article( $title );
	$watching = $title->userIsWatching();

	if ( $watch ) {
		if ( !$watching ) {
			$dbw = wfGetDB( DB_MASTER );
			$dbw->begin();
			$ok = $article->doWatch();
			$dbw->commit();
		}
	} else {
		if ( $watching ) {
			$dbw = wfGetDB( DB_MASTER );
			$dbw->begin();
			$ok = $article->doUnwatch();
			$dbw->commit();
		}
	}
	// Something stopped the change
	if ( isset( $ok ) && !$ok ) {
		return '<err#>';
	}
	if ( $watch ) {
		return '<w#>' . wfMsgExt( 'addedwatchtext', array( 'parse' ), $title->getPrefixedText() );
	} else {
		return '<u#>' . wfMsgExt( 'removedwatchtext', array( 'parse' ), $title->getPrefixedText() );
	}
}

/**
 * Called in some places (currently just extensions)
 * to get the thumbnail URL for a given file at a given resolution.
 */
function wfAjaxGetThumbnailUrl( $file, $width, $height ) {
	$file = wfFindFile( $file );

	if ( !$file || !$file->exists() )
		return null;

	$url = $file->getThumbnail( $width, $height )->url;

	return $url;
}

/**
 * Called in some places (currently just extensions)
 * to get the URL for a given file.
 */
function wfAjaxGetFileUrl( $file ) {
	$file = wfFindFile( $file );

	if ( !$file || !$file->exists() )
		return null;

	$url = $file->getUrl();

	return $url;
}
